(Fonte: Lattes)
Índice h a partir de 2011
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Patologia, Faculdade de Medicina - Docente
LIM/49 - Laboratório de Protozoologia, Hospital das Clínicas, Faculdade de Medicina - Líder

Resultados de Busca

Agora exibindo 1 - 10 de 74
  • article 1 Citação(ões) na Scopus
    Efficiency of a Single well IgG, IgM and IgA Anti T. gondii Fluorimetric Assay for Pre-natal Screening for Congenital Toxoplasmosis
    (2022) RODRIGUES, Jaqueline Polizeli; ANDRADE JUNIOR, Heitor Franco de
    Toxoplasmosis, worldwide protozoan disease, is usually benign, except when acute disease occurs in pregnant women, resulting in fetal infection with deaths or high morbidity after birth. Treatment blocks fetal infection or damage after infection, imposing a quick and effective diagnosis. Maternal infection is mostly asymptomatic thus regular serology are the main tool for detect seroconversion and acute infection in prenatal care. Screening test for specific anti T. gondii IgG, IgM and IgA must be quick, cheaper and available for the prenatal care. Fluorescent solid phase assays appears as a good alternative as they allow one well detection of IgG and IgM aside to allow high throughput in 384 wells. Here, we standardize and analyze a single well anti-T. gondii IgG, IgM and IgA immunosorbent fluorescent assay in a large sample of a public hospital. We construct conjugates for each immunoglobulin with specific fluorophores, which allows concomitant detection in a microplate fluorimeter, with stability and reproducibility, allowing cheaper 384 wells use. Tested in our 600 mother samples from a large public hospital, they presented the same reactivity as standard routine tests, but with adequate IgM and IgA screening, as adequately standardized in house ELISA, while the design of most commercial assays give false positive results. The few TFISA positive IgG, IgM and IgA samples also had low avidity IgG, confirming recent infection. TFISA will help a screening toxoplasmosis in pregnancy program in large cities, with , allowing testing large numbers of samples at low cost and must be considered for other serological purposes.
  • conferenceObject
    (2017) COSTA, Andrea da; ZORGI, Nahiara E.; NASCIMENTO, Nanci do; GALISTEO JR., Andres J.; ANDRADE JR., Heitor F. de
  • article 3 Citação(ões) na Scopus
    Indirect Evidence of Circulating Parasite Hapten Immune Complexes in Visceral Leishmaniasis
    (2019) CARVALHO, Camila Aparecida de; FERRAO, Thiago Fidelis; HIRAMOTO, Roberto Mitsuyoshi; PARTATA, Anette Kelsei; ANDRADE JUNIOR, Heitor Franco de
    Background: Hypergammaglobulinemia is present in visceral leishmaniasis (VL), inducing the formation of immune complexes (ICs), which interferes in conventional serology. Parasitic haptens block antibodies, making it difficult to identify and detect them. ICs could be determined indirectly by acid dissociative ELISA (DE) seroconversion in natural and experimental VL. Methods: We determined the frequency of samples that seroconverted in DE or presented a 10% increase in DE (Delta DE) in 3 types of VLs-hamster, canine, and human samples-with larger antigen determination by direct antigen capture in experimental samples. Results: The Delta DE frequency is increased in all VL models: human (34%), canine (27%), and hamster (25%) samples. Seroconversion was present in hamster (14%), dog (1%), and human (6%) samples. During experimental infection, higher frequencies (28%) of circulating antigens were observed at the 30th day, associated with higher Delta DE (47%) and seroconversion (22%), with lower frequencies in other periods. Conclusions: The frequency of Delta ED and seroconversion samples found in natural and experimental infection suggests that specific antibodies can be blocked by low molecular weight antigens that interfere qualitatively (seroconversion) or quantitatively (Delta DE) in serology. Several antigen types may be involved, as high molecular weight proteins and low molecular weight glycoconjugates. The higher frequency of those indirect demonstrations of antibody-blocking antigen or haptens that could be acid-removed in VL has implications for the development of assays for detection of circulating or antibody-bound 1- to 3-kDa antigens, which could interfere in diagnosis and also in the immune response of the host.
  • article 19 Citação(ões) na Scopus
    Immunity in the spleen and blood of mice immunized with irradiated Toxoplasma gondii tachyzoites
    (2016) ZORGI, Nahiara Esteves; GALISTEO JR., Andres Jimenez; SATO, Maria Notomi; NASCIMENTO, Nanci do; ANDRADE JR., Heitor Franco de
    Toxoplasma gondii infection induces a strong and long-lasting immune response that is able to prevent most reinfections but allows tissue cysts. Irradiated, sterilized T. gondii tachyzoites are an interesting vaccine, and they induce immunity that is similar to infection, but without cysts. In this study, we evaluated the cellular immune response in the blood and spleen of mice immunized with this preparation by mouth (v.o.) or intraperitoneally (i.p.) and analyzed the protection after challenge with viable parasites. BALB/c mice were immunized with three i.p. or v.o. doses of irradiated T. gondii tachyzoites. Oral challenge with ten cysts of the ME-49 or VEG strain at 90 days after the last dose resulted in high levels of protection with low parasite burden in the immunized animals. There were higher levels of specific IgG, IgA and IgM antibodies in the serum, and the i.p. immunized mice had higher levels of the high-affinity IgG and IgM antibodies than the orally immunized mice, which had more high-affinity IgA antibodies. B cells (CD19(+)), plasma cells (CD138(+)) and the CD4(+) and CD8(+) T cell populations were increased in both the blood and spleen. Cells from the spleen of the i.p. immunized mice also showed antigen-induced production of interleukin-10 (IL-10), interferon gamma (IFN-gamma) and interleukin 4 (IL-4). The CD4(+) T cells, B cells and likely CD8(+) T cells from the spleens of the i.p. immunized mice proliferated with a specific antigen. The protection was correlated with the spleen and blood CD8(+) T cell, high-affinity IgG and IgM and antigen-induced IL-10 and IL-4 production. Immunization with irradiated T. gondii tachyzoites induces an immune response that is mediated by B cells and CD4(+) and CD8(+) T cells, with increased humoral and cellular immune responses that are necessary for host protection after infection. The vaccine is similar to natural infection, but free of tissue cysts; this immunity restrains infection at challenge and can be an attractive and efficient model for vaccine development in toxoplasmosis.
  • article 21 Citação(ões) na Scopus
    In vitro action of antiparasitic drugs, especially artesunate, against Toxoplasma gondii
    (2012) GOMES, Thais Cobellis; ANDRADE JUNIOR, Heitor Franco de; LESCANO, Susana Angelica Zevallos; AMATO-NETO, Vicente
    Introduction: Toxoplasmosis is usually a benign infection, except in the event of ocular, central nervous system (CNS), or congenital disease and particularly when the patient is immunocompromised. Treatment consists of drugs that frequently cause adverse effects; thus, newer, more effective drugs are needed. In this study, the possible activity of artesunate, a drug successfully being used for the treatment of malaria, on Toxoplasma gondii growth in cell culture is evaluated and compared with the action of drugs that are already being used against this parasite. Methods: LLC-MK2 cells were cultivated in RPMI medium, kept in disposable plastic bottles, and incubated at 36 degrees C with 5% CO2. Tachyzoites of the RH strain were used. The following drugs were tested: artesunate, cotrimoxazole, pentamidine, pyrimethamine, quinine, and trimethoprim. The effects of these drugs on tachyzoites and LLC-MK2 cells were analyzed using nonlinear regression analysis with Prism 3.0 software. Results: Artesunate showed a mean tachyzoite inhibitory concentration (IC50) of 0.075 mu M and an LLC MK2 toxicity of 2.003 mu M. Pyrimethamine was effective at an IC50 of 0.482 mu M and a toxicity of 11.178 mu M. Trimethoprim alone was effective against the in vitro parasite. Cotrimoxazole also was effective against the parasite but at higher concentrations than those observed for artesunate and pyrimethamine. Pentamidine and quinine had no inhibitory effect over tachyzoites. Conclusions: Artesunate is proven in vitro to be a useful alternative for the treatment of toxoplasmosis, implying a subsequent in vivo effect and suggesting the mechanism of this drug against the parasite.
  • article 8 Citação(ões) na Scopus
    (2016) SUMITA, Laura Masami; RODRIGUES, Jaqueline Polizeli; FERREIRA, Noely Evangelista; FELIX, Alvina Clara; SOUZA, Nathalia Caroline Santiago; MACHADO, Clarisse Martins; ANDRADE JUNIOR, Heitor Franco de
    Zika virus (ZKV) infection is a huge public health problem in Brazil because of the increased incidence of microcephaly in neonates from infected mothers. Detection of specific IgG antibodies in maternal serum samples constitutes an important approach for diagnosing ZKV infection and evaluating its relationship with neonatal microcephaly. However, as there is no serological test produced in Brazil to detect IgM and IgG antibodies against ZKV, we sought to examine specific IgG in serum samples from patients or suspected mothers to detect previous infection and to test for specificity with regard to flaviviral infections occurring in the same area. Brazilian Zika virus native antigens were obtained from infected Vero cell layers or free virions in the culture medium and then used in ELISA. We tested sera from eight ZKV RNA-diagnosed infected patients (ZKVR), seven neonates with microcephaly and their mothers after delivery (MM), 140 dengue virus IgM-positive (DM) and IgG (DG)-positive patients, and 100 yellow fever (YF)-vaccinated patients. According to the ELISA, ZKVR samples were mostly positive (7/8), and all the MM serum samples were positive for ZKV IgG (7/7). In contrast, cross-reactions for dengue or yellow fever-vaccinated patients were observed, including DM (48/95), DG (10/45) or YF (3/100) serum samples; however, these cross-reactions exhibited low antigen avidity so that 6 M urea largely removed this cross-reactivity, with only a few cross-reacting samples remaining (8/140). ELISA based on extracted virions was much more specific, with all ZKVR (8/8) and MM sera being positive for ZKV IgG (7/7) and only borderline cross-reactivity found for DM (6/95), DG (3/45) or YF (4/100)-vaccinated serum samples. This technique (ELISA) can identify specific IgG in ZKV-infected patients and may be helpful in diagnosing congenital infetions after maternal RNA virus clearance or in epidemiological studies.
  • article 1 Citação(ões) na Scopus
    Preventive measures for "Pet Friendly" lodging facilities: association of Leishmaniasis expansion route in Sao Paulo and preventive measures for regional animals displacement
    (2017) CARVALHO, Camila Aparecida de; FUJITA, Dennis Minoru; NALI, Luiz Henrique da Silva; ANDRADE JUNIOR, Heitor Franco de; HIRAMOTO, Roberto Mitsuyoshi
  • article 102 Citação(ões) na Scopus
    Thymol and eugenol derivatives as potential antileishmanial agents
    (2014) MORAIS, Selene Maia de; VILA-NOVA, Nadja Soares; BEVILAQUA, Claudia Maria Leal; RONDON, Fernanda Cristina; LOBO, Carlos Henrique; MOURA, Arlindo de Alencar Araripe Noronha; SALES, Antonia Debora; RODRIGUES, Ana Paula Ribeiro; FIGUEREIDO, Jose Ricardo de; CAMPELLO, Claudio Cabral; WILSON, Mary E.; ANDRADE JR., Heitor Franco de
    In Northeastern Brazil visceral leishmaniasis is endemic with lethal cases among humans and dogs. Treatment is toxic and 5-10% of humans die despite treatment. The aim of this work was to survey natural active compounds to find new molecules with high activity and low toxicity against Leishmania infantum chagasi. The compounds thymol and eugenol were chosen to be starting compounds to synthesize acetyl and benzoyl derivatives and to test their antileishmanial activity in vitro and in vivo against L. i. chagasi. A screening assay using luciferase-expressing promastigotes was used to measure the growth inhibition of promastigotes, and an ELISA in situ was performed to evaluate the growth inhibition of amastigote. For the in vivo assay, thymol and eugenol derivatives were given IP to BALB/c mice at 100 mg/kg/day for 30 days. The thymol derivatives demonstrated the greater activity than the eugenol derivatives, and benzoyl-thymol was the best inhibitor (8.67 +/- 0.28 mu g/mL). All compounds demonstrated similar activity against amastigotes, and acetyl-thymol was more active than thymol and the positive control drug amphotericin B. Immunohistochemistry demonstrated the presence of Leishmania amastigote only in the spleen but not the liver of mice treated with acetyl-thymol. Thus, these synthesized derivatives demonstrated anti-leishmanial activity both in vitro and in vivo. These may constitute useful compounds to generate new agents for treatment of leishmaniasis.
  • article 29 Citação(ões) na Scopus
    In situ apoptosis of adaptive immune cells and the cellular escape of rabies virus in CNS from patients with human rabies transmitted by Desmodus rotundus
    (2011) FERNANDES, Elaine Raniero; ANDRADE JR., Heitor Franco de; LANCELLOTTI, Carmen Lucia Penteado; QUARESMA, Juarez Antonio Simoes; DEMACHKI, Samia; VASCONCELOS, Pedro Fernando da Costa; DUARTE, Maria Irma Seixas
    The aim of the current study was to investigate the apoptosis of neurons, astrocytes and immune cells from human patients that were infected with rabies virus by vampire bats bite. Apoptotic neurons were identified by their morphology and immune cells were identified using double immunostaining. There were very few apoptotic neurons present in infected tissue samples, but there was an increase of apoptotic infiltrating CD4+ and TCD8+ adaptive immune cells in the rabies infected tissue. No apoptosis was present in NK, macrophage and astrocytes. The dissemination of the human rabies virus within an infected host may be mediated by viral escape of the virus from an infected cell and may involve an anti-apoptotic mechanism, which does not kill the neuron or pro-apoptosis of TCD4+ and TCD8+ lymphocytes and which allows for increased proliferation of the virus within the CNS by attenuation of the adaptive immune response.
  • article
    (2015) NASARE, Alex M.; TEDESCO, Roberto C.; CRISTOVAM, Priscila C.; CENEDESE, Marcos A.; GALISTEO JR., Andres J.; ANDRADE JR., Heitor F.; GOMES, Jose Alvaro P.; GUIMARAES, Erik V.; BARBOSA, Helene S.; ALONSO, Luis G.
    HSP90B1 is a gene that codifies heat shock protein 108 (HSP108) that belongs to a group of proteins induced under stress situation, and it has close relation with the nervous system, especially in the retina. Toxoplasma gondii causes ocular toxoplasmosis that has been associated with a late manifestation of the congenital toxoplasmosis although experimental models show that morphological alterations are already present during embryological development. Here, we used 18 eyes of Gallus domesticus embryos in 7th and 20th embryonic days to establish a model of congenital ocular toxoplasmosis, experimentally infected in its fifth day correlating with HSP90B1 gene expression. Embryos' eyes were histologically evaluated, and gene expression was performed by real-time polymerase chain reaction (PCR). Our data showed parasite present in the choroid, unusual migration of retinal pigment epithelium, and chorioretinal scars, and a tendency to a lower expression of the HSP90B1 gene upon experimental infection. This is a promising model to better understand T. gondii etiopathogeny.